This cheap, ingenious strip can detect Zika virus in your spit

The plastic, color-changing strips. Alexandre Brolo When Alexandre Brolo was growing up in Brazil, government workers dropped by his house every year to talk about mosquitoes.

Their mission: to warn people about dengue fever and locate areas where the mosquitoes that spread the disease were breeding.

"Every year, you have that issue of dengue," Brolo told Tech Insider, "and every time the response from the government seems to be always the same."

Brazil alone reported 1.5 million of the nearly 2.4 million dengue cases worldwide in 2015. This number is likely much higher because not everyone who gets it is diagnosed.

If health care workers could get a better handle on how many people are actually getting the disease, it could help them fight it more effectively. And now that Zika— which is spread by the same mosquitoes as dengue and can cause debilitating defects in babies and complications in adults— has taken hold in Latin America, health systems need all the help they can get.

Brolo, now a chemist at the University of Victoria, wanted to apply his expertise in nanotechnology to make something that could help beleaguered governments fight dengue. Workers are already in the field interacting with people who are getting infected, he thought — so why not give them cheap, easy tools to make their roles more effective?

The gold standard for diagnosing viruses like dengue and Zika today is a blood test. Yet most door-to-door health officials are not highly trained, he said, so having them administer blood tests that labs need to process isn't realistic.

"The parameters were to find a technology that was inexpensive, that can be done in the field, and that does not require any training — something that could provide a tool to these health officials who go door to door every year with only a brochure in their hand," he said.

In response, Brolo developed cheap, plastic strips that can diagnose the disease in people's spit, and a pilot test in Brazil showed they were up to 60% effective — a number he hopes to improve over time.

Switching the strips to Zika

Two of Brolo's students, Sabrina and Regie — who are also Brazilian — show the plastic Zika strips in the lab. Alexandre Brolo When the Zika outbreak started ravaging Brazil, he adapted the strips so that they could detect that virus, which is very similar to dengue.

The strips respond to Zika-caused antibodies — proteins the body creates to fight specific diseases — using proteins encased in nanoparticles. When Zika antibodies are present, the strips change color.

Brolo said the Zika strips would work within five to 15 days of getting the infection, so they could diagnose people who currently have the disease — even if they don't know it. This would be extremely useful, since only about one in five patients has symptoms.

So far, Brolo has only tested the Zika strips in his lab. But he plans to study them this summer in Brazil, during a pilot test to measure how effective they are compared to his dengue strips.

If they work, Brolo thinks they could be in the hands of the health care workers within a year and a half. He's already received a $50,000 grant from Grand Challenges Canada, though it likely won't be enough to push the spit strips all the way to an in-the-field tool.

At only about $5 per strip — a figure Brolo thinks he can get down to $1 once they're mass-produced — the test could increase the odds that more people get tested for Zika and dengue. Meanwhile, he says blood tests can cost more than $100.

Since there are no vaccines or drugs currently available to treat or prevent Zika, the best defense against the virus right now is to kill the mosquitoes that spread it.

A health worker sprays insecticide to combat the Aedes aegypti mosquitoes that transmit the Zika virus in Rio de Janeiro, Brazil on Tuesday, Jan. 26, 2016. Leo Correa/AP Photo To know where to fumigate, health workers first have to know where the virus is spreading.

That's why making diagnoses is so critical.

"Based on the discussions I had with people in Brazil, they say even if you detect something, if you can say yes or no for dengue, chikungunya, or Zika as a group, it's already a good tool," Brolo said. "Because this tells you more or less where the mosquitoes are, and then they can go and kill it."

He dreams of developing a strip that could detect all three diseases on day — all from a few drops of spit that people can test at a hospital or right in people's homes.

"That's the dream," Brolo said. "I think in science, you've gotta dream and then you've got to see if you can go for it."